For the code updates... here is my thinking.
I get the game and I play it a bunch. I start to notice changes I'd like to make and I start taking notes of my ideas around this.
I also go online and read up on the reviews of the game on Pinside, RGP, and IPDB. What are the common complaints that are code/rules related? I add those to my notes.
For JP, I think it's safe to say the most common complaints are:
1) qualifying multi-ball is handed to the player on ball 3. most players want to earn multiball.
2) stampede is always the first mode.
3) ball save is too short.
4) some modes are "throwaway modes" and are not worth playing or the risk vs. reward is not great enough.
So... that is my starting point.
I start knocking those complaints down and fixing them.
I also engage the community to see what they are thinking. I get lots of great feedback and suggestions. I get a bunch of PM's and emails about their thoughts. Every time, so far, one individual steps forward and becomes a "partner". A person who has a deep knowledge of the game and pinball rules in general. A person who I bounce everything off of to see what he thinks. A person who understands the game and understands what's possible and what's "too crazy" and makes suggestions along the way.
Then it's taking a step back and taking a look at everything in the game. How does everything else play? How is the balance of all other parts of the game? Can anything be tweaked? Are there features or shots in the game that players don't shoot for or care about because the reward is not worth the risk? Are there any under appreciated things in the game that could use a little love?
Usually, it's just a little nudge here and there. A fine tuning of what already exists. It's 20 years of being able to look at a game and then give it a nip here and a tuck there.
It's also about looking at other parts of the game... things like "wouldn't be be cool if the 40 second T-Rex diagnostics could be skipped?" and "it would be great if the skill shot wasn't the exact same pattern every time!" and "hmmm, here's a couple unused voice calls that could be integrated into the game." and "it might be cool if the Shoot Again insert flashed when ball save was active!".
All the changes are in the spirit of the original game. I want the game to be the best game it can possibly be and still be the same Jurassic Park that everyone grew up with and loved over the years. Never have I wanted to make any radical changes or completely rewrite the game.
So in the end... it's a better game. In the end, for me anyway, it makes the game a "keeper".